The present invention relates to a stagelessly adjustable telescopic walking stick having a position retaining device so as to permit the walking stick to be extended to any length within a limited range and be firmly retained at any selected length so as to permit the telescopic walking stick to be used by people of various physical sizes.
In general, walking sticks are manufactured in a number of fixed sizes and people of different physical sizes must choose a proper walking stick best meet their physical sizes. Such way of producing walking sticks of fixed sizes make the stocks in the warehouse of a factory or stores piled up easily.
To solve the problem, length adjustable walking sticks have been developed for many years. The conventional adjustable walking sticks are designed to have an upper pipe and a lower pipe having a plurality of evenly spaced retaining holes defined thereon. The upper pipe is equipped with a pair of retractable locking buttons which can be in selective engagement with the retaining holes of the lower pipe, making the walking stick adjustable in length.
However, this prior art walking stick has a number of inherent disadvantages given as below:
1. The evenly spaced retaining holes on the lower pipe are not defined in such a manner that a precise length can be easily obtained in one aspect; and the operation on the retaining buttons and the selection of proper retaining holes are relatively difficult for the aged people in another aspect.
2. The disposition of the retaining holes on the lower pipe makes the strength of the lower pipe weakened and the surface of the same spoiled.
3. The drilling of the retaining holes on the lower pipe makes the production of a walking stick complex and the manufacturing cost thereof relatively high.
4. A personal walking stick is usually used only by an individual constantly and the retaining holes are almost fixed without shift, rendering easy damage to the retaining holes and shortening the operation life of such a walking, stick after a period of time.
The inventor has noticed such problems associated with conventional walking sticks and came up with a stagelessly adjustable walking stick equipped with specific position retaining devices as disclosed in the present invention.
Therefore, the primary object of the present invention is to provide a stagelessly adjustable walking stick having a position, retaining device which enables a user to vary the length of the walking stick in a random manner within a limited range.
Another object of the present invention is to provide a stagelessly adjustable walking stick having a position retaining device equipped with an eccentrically driven retainer and having an expandable plastic tube having inner threads. The plastic tube is made up of two separable portions bound together by a C-shaped clamp, one portion has an eccentrically located engagement protrusion to which an eccentric circular disk is secured by a screw. A cone-shaped taper means having one end secured to one end of a lower pipe of a walking stick and having the other end provided with a threaded post which can be engaged with the inner threaded face of the plastic tube and make the taper means proceed forwardly or withdraw backwardly, resulting in the outward expansion of the clamp bound plastic tube when the lower pipe is rotated to move upwardly, making the eccentric circular disk and the eccentric retainer both housed in the upper pipe abut against the inner wall of the upper pipe respectively in such a manner that the retainer of the taper means mounted onto the end of the lower pipe can proceed forwardly to expand outwardly the plastic tube whereby the upper pipe and the lower pipe can be firmly locked together by the expanded plastic tube at a selected length.
One further object of the present invention is to provide a stagelessly adjustable walking stick having a position retaining device having an eccentric circular disk secured to an eccentrically operated retainer having an eccentric securing member for the fixing of the circular disk by a screw. The retainer has a tapered face at the top with an inner threaded tubular extension projected downwardly therefrom so that a taper means attached to the end of the lower pipe and having an outerly threaded post projected therefrom can adjustably engaged with the retainer. A plastic locking tube having a longitudinally split opening is disposed between the eccentric retainer and the taper means whereby when the eccentric circular disk and the retainer are housed in the upper pipe of a walking stick, the split plastic tube will be forced to outwardly expand to abut tightly against the inner wall of the upper pipe as a result of the taper means secured to the lower pipe proceeding forwardly due to the rotation of the lower pipe by a person. The eccentric circular disk and the eccentric retainer are designed to abut firmly against the inner wall of the upper pipe when the lower pipe is rotated to make the outerly threaded post of the taper means engaged with the innerly threaded tubular extension, making the eccentric circular disk and the eccentric retainer rotated separately to such a position that the eccentric circular disk and the eccentric retainer are in a locking abutment against the inner wall of the upper pipe, guaranting the taper means to be able to effectively proceed against the plastic locking tube to make the same outwardly expanded.
One still further object of the present invention is to provide a stagelessly adjustable walking stick having a position retaining device that is equipped with a plastic retainer cap having a tubular passage. The plastic retainer cap is divided into four symmetric portions by two orthogonally defined splitting cuts crisscrossing at the summit of the cap. The tubular passage is provided with inner threads on the wall thereof so as to permit a threaded post having a tapered end and secured to the top end of the lower pipe to be rotatably engaged with the plastic retainer cap. The innerly threaded tubular passage extends most of the plastic retainer cap with a section thereof, adjacent the four portion split top end, left blank whereby when the tapered end of the threaded post is made to move forwardly as a result of the rotation of the lower pipe, the four split portions of the plastic retainer cap are urged to outwardly expand to firmly abut against the inner wall of the upper pipe so as to lock the lower pipe in position to the upper pipe after a suitable length of the walking stick is selected.